**3.5.1 Effect of grammage and bauxite on degradation period**

Fig.3-11 showed the effects of grammage and bauxite on degradation period when other factors were held at 0 level. Degradation period gradually increased with the increase of bauxite and grammage, the maximum occurred when bauxite was held at 6%, and grammage was held at 110 g/m2, because of the increase of grammage, the number of fibres grew, the bonding capacity between fibres enhanced, the amount of bauxite increased, the ability of fibre that absorbing additives enhanced, which made dry tensile strength and wet tensile strength of film become larger, the degradation period of film increase.

Fig. 3-11. Response surface and contour plots for the effects of grammage and bauxite on the degradation period: beating degree was held at 40SR°, rosin was held at 0.8%,wet strength agent was held at 1.8%

Fig. 3-10. Response surface and contour plots for the effects of bauxite and wet strength agent on wet tensile strength: beating degree was held at 40SR°, grammage was held at

Bauxie/%

Fig.3-11 showed the effects of grammage and bauxite on degradation period when other factors were held at 0 level. Degradation period gradually increased with the increase of bauxite and grammage, the maximum occurred when bauxite was held at 6%, and grammage was held at 110 g/m2, because of the increase of grammage, the number of fibres grew, the bonding capacity between fibres enhanced, the amount of bauxite increased, the ability of fibre that absorbing additives enhanced, which made dry tensile strength and wet

Fig. 3-11. Response surface and contour plots for the effects of grammage and bauxite on the degradation period: beating degree was held at 40SR°, rosin was held at 0.8%,wet strength

tensile strength of film become larger, the degradation period of film increase.

80 g/m2,rosin was held at 0.8%

agent was held at 1.8%

**3.5 Effect of interaction factors on degradation period** 

**3.5.1 Effect of grammage and bauxite on degradation period** 

#### **3.5.2 Effect of bauxite and wet strength agent on degradation period**

Fig.3-12 showed the effects of bauxite and wet strength agent on degradation period when other factors were held at 0 level. Degradation period gradually increased with the increase of bauxite and wet strength agent, the maximum occurred when bauxite was held at 6%, and wet strength agent was held at 3%, wet strength agent at a suitable amount could improve the wet tensile strength of film, and make degradation period grow.

Fig. 3-12. Response surface and contour plots for the effects of bauxite and wet strength agent on the degradation period: beating degree was held at 40SR°, grammage was held at 80 g/m2,rosin was held at 0.8%

Fig. 3-13. Optimum analysis plot: rosin was held at 0.8%, bauxite was held at 4%, wet strength agent was held at 1.8%.

Study on Manufacturing Technology and Performance of Biogas Residue Film 285

A 65 33.70 12.46 0.248 70 B 80 36.30 14.40 0.316 70 C 100 30.69 10.40 0.385 70 D 55 39.16 13.46 0.099 70 E 9 1.50 - 0.011 70

The effect scene of different treatments on the weed amount in the case of cultivating eggplant was shown in Fig.4-1. Weed amount of mulching was markedly less than the control, and weed amount of plastic film was more than biogas residue films. In the period of observation, weeds were flourished under the plastic film or even broke plastic mulch. Weeds mainly grew from transplanted hole and rupture to all the treatments, and making

(a) A (b) B (c) C

(d) D (e) E (f) control

Fig. 4-1. The effect scene of different treatments on the weed amount in the case of

Wet tensile strength N

Thickness mm

Width cm

Dry tensile strength N

Notes: A,B,C were biogas residue fibre mulch of different grammage, respectively; D was black

biodegradable mulching added in activated carbon; E was plastic film.

**4.1 Effect of different treatments on the weed amount** 

Treatment Grammage

the film rupture expands.

cultivating eggplant

g/m2

Table 4-1. Performance index of the treatments
